Lift mechanism for bleachers and the like



Aug. 15, 1967 H. F. BAHR 3,335,533

LIFT MECHANISM FOR BLEACHERS AND THE LIKE Filed March 27, 1964 5 Sheets-Sheet 1 F-\6.( '22 we K a 0 4o INVENTOR. 4 Haaow F. 8mm

ATTORNEY H. F. BAHR Aug. 15, 1967 LIFT MECHANISM FOR BLEACHERS AND THE LIKE Filed March 27, 1964 5 Sheets-Sheet m To INVENTOR. HMKQLQ F. Bang A-r'r RNFLY N M. N

Aug. 15, 1967 H. F. BAHR LIFT MECHANISM FOP. BLEACHERS AND THE LIKE 5 Sheets-Sheet Filed March 27, 1964 WWW ATTCRNEY H. F. BAHR Aug. 15, 1967 LIFT MECHANISM FOR BLEACHERS AND THE LIKE 5 Sheets-Sheet 4 Filed March 27, 1964 FUal How

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INVENTOR H8 IZZ 4 I46 I48 HAROLD F. B R w. W

ATTORNEY Aug. 15, 1967 H. F. BAHR 3,335,533

LIFT MECHANISM FOR BLEACHERS AND THE LIKE Filed March 2'7, 1964 5 SheetsSheet tIZZ I36 (NVENTOR HAROLD F. Bang MWMM ATTORNEY fit 3,335,533 LIFT MECHANISM FGR BLEACHERS AND THE LIKE Harold F. Bahr, Milwaukee, Wis., assignor, by mesne assignments, to Automatic Sprinkler Corporation of America, Cleveland, Ohio, a corporation of Ohio Filed Mar. 27, 1964, Ser. No. 355,184 10 Claims. (61. 52122) This invention relates to an improved lift mechanism for moving large and bulky structures such as telescoping bleachers and chair risers and the like.

The primary object of this invention is to provide a lift mechanism which is of relatively simple construction, is easy to operate and is efiective to safely lift and move an entire bleacher section.

Another object is to provide a lift mechanism which is capable of lifting and transporting an entire bleacher section while maintaining good balance and stability.

Another object is to provide a lift mechanism which can be readily detached from the structure to be moved so that one lift mechanism can be used to move several structural units if desired.

Other objects and advantages will be pointed out in, or be apparent from, the specification and claims, as will obvious modifications of the two embodiments shown in the drawings, in which:

FIG. 1 is a side elevation view of a bleacher assembly with the lift mechanism of the present invention positioned in operating position at the rear thereof and with the bleacher sections in extended position;

FIG. 2 is a fragmentary rear elevation view of the structure shown in FIG. 1 but with the bleacher in retacted position;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2.

FIGS. 4 and 5 are fragmentary side elevation views of the two basic parts of the lift mechanism shown disassembled from each other;

FIG. 6 is a fragmentary sectional view taken along line 66 of FIG. 3;

FIG. 7 is a fragmentary sectional view taken along line 77 of FIG. 3;

FIG. 8 is a fragmentary rear elevation view (with parts broken away) of a modified form of the invention particularly adapted for use with a seating structure of heavy construction such as that employed in a telescoping or folding chair riser;

FIG. 9 is a vertical sectional view (with parts broken away) taken along line 9-9 of FIG. 8;

FIG. 10 is a horizontal sectional view taken along line 10-10 of FIG. 9;

FIG. 11 is a fragmentary side elevation View of the wheeled support assembly with the lift assembly disassembled therefrom;

FIG. 12 is a horizontal sectional view taken along line 1212 of FIG. 9;

FIG. 13 is a sectional view taken along line 1313 of FIG. 9; and

FIG. 14 is an enlarged elevation view (with parts broken away) of the stabilizing means for the lift mechanism.

While the lift mechanism of this invention may be employed to advantage with various types of structures, it is particularly well adapted for use with telescoping bleacher seats and chair risers of the type used in gymnasiurns, auditoriums and the like.

A bleacher seat assembly of the type referred to is shown in FIG. 1 and is indicated generally by the reference numeral 10. The various sections of the assembly 10 are of similar construction with each successive section being of a different height so that they will nest together when retracted. Each section includes a pair of spaced horizontal carriage members 12, 12 and a pair of spaced vertical column assemblies 14, 14 fastened to the carriage members as shown. The pairs of carriage members 12, 12 are interconnected to provide a self-supporting structure by suitable back braces (not shown).

To each column assembly 14 is fastened a horizontal seat angle 16 extending forwardly from the columns and parallel to carriage members 12 at the desired height depending on the particular section involved. Angles 16 have seat brackets 18 fastened thereto for mounting riser and seat boards 20 and 22, respectively, at the forward ends of the angles. Foot boards 24 are also mounted on angles 16 as shown.

Each section of the bleacher assembly is supported for extending and retracting rolling movement by two pairs of wheels 26 mounted between the legs of the channelshaped carriage members 12 as clearly shown in FIG. 2.

As shown in FIG. 2, each pair of carriage members for the respective bleacher sections are spaced so that each successive section going from front to rear fits inside the next section. Similarly, as shown in FIG. 1, the seat height of each successive section going from rear to front decreases so that as each section is rolled rearwardly it will nest underneath and between its next adjacent section to the rear. When the bleacher assembly is extended as shown in FIG. 1, the seat angle 16 of one section is supported on the top of a column 14 of the next adjacent section to the front. The various sections of the bleacher assembly may be held and retained in either retracted or extended position by a row lock and trip mechanism like that shown in copending application Ser. No. 29,853 now Patent No. 3,157,916 assigned to the assignee of this application.

Referring now to the lift mechanism of this invention, FIGS. 4 and 5 show the two basic assemblies of such mechanism. FIG. 4 shows a wheeled support assembly 28 and FIG. 5 shows a lift assembly 30 which, when assembled together, cooperate to provide the several objects of this invention. As shown in FIG. 2, a spaced pair of assembled support assemblies 28, 28 and lift assemblies 30, 30 are fastened together by a horizontal I-beam 32 and a pair of cross braces 34, 34 to produce a self-supporting unit.

Each support assembly 28 is comprised of a horizontal channel member 36 and a vertical tubular guide rail assembly 38 mounted thereon. Each channel 36 is provided with a pair of castors 40, 40 for wheeling the entire unit along the floor when desired. Guide rail assembly 38 is comprised of a pair of spaced tubes 42, 42 rigidly secured to each other by a plurality of cross tube supports 44 welded to the vertical tubes as shown. As shown clearly in FIGS. 3 and 7, a suitable lifting means such as a hydraulic ram unit 46 having a piston 47 is mounted on support assembly 28 by means of a mounting structure comprised of plates 48, 50 and 52 and a pair of U-bolts 54, 54. Plate 48 is provided with an opening 56 therein and a second support plate 49 is provided with a second opening 51 therein through which a hydraulic oil line (not shown) is extended for connecting ram 46 with a pump unit 45 mounted on the side of channel 58, as shown in FIGS. 1 and 2.

Lift assembly 30 (FIGS. 3 and 5) is comprised of a vertically extending formed channel 58 having a pair of retaining flanges 60, 60 thereon and a plurality of lifting angle members 62 fastened thereto by welding or other suitable means. Also fastened to channel 58 are a top footboard angle 64 and a top seat angle 66. Just as in the bleacher structure previously described with reference to FIG. 1, footboard angle 64 is provided with a seat iron 68 for mounting riser and seat boards 70 and 72 thereon. A footboard 74 is also mounted thereon. Similarly, top seat angle 66 is provided with a top seat board 76 and riser 78 mounted thereon. Also mounted on channel 58 is a gusset plate 80 and a lift plate 82 adapted for cooperation with the lift ram 46 on the support assembly as will be hereinafter described.

As shown in FIGS. 3, 6 and 7, lift assembly 30 is slidably supported on support assembly 28 with tubes 42, 42 slidably engaged in opposite ends of channel member 58 with the retaining flanges 60, 60 of the channel serving to retain the channel in place on the tubes. A pair of alignment rollers 84 and 86 rotatably mounted between channel 58 and the second from the bottom lift angle 62 and a single alignment roller 88 is mounted between channel 58 and the top footboard angle 64. Rollers 84, 86 and 88 serve to prevent binding of the channel 58 on the guide rail assembly 38 to thus insure a smooth sliding relationship between the two assemblies even under the heavy loads experienced when lifting a bleacher seat unit of the type shown in the drawings.

As shown in FIGS. 3 and 7, when the lift mechanism is fully assembled lift plate 82 on the lift assembly will be positioned directly over the end of the operating piston 47 of ram 46 so that upon actuation of the ram the entire lift assembly 30 including lift angles 62 will be moved upwardly with respect to the support assembly 28.

An optional feature of the present invention is the provision of a brake assembly 90 which is comprised of a tube 92 fastened between channel 58 and the second from the bottom seat angle 62 by means of a pin 94 and a collar 96 (FIG. Tube 92 is provided with a brake pad angle 98 mounted on the lower end thereof so that when the lift mechanism is in its down position as shown in FIGS. 3 and 7, pad 98 will engage the floor and serve as a brake to prevent the lift mechanism from rolling.

From the foregoing it will be apparent that to operate the lift mechanism of this invention, the first step is to position the mechanism at the rear of the bleacher unit as shown in FIGS. 1, 2 and 3. It will be appreciated that in the specific embodiment of the invention shown in the drawings and described above, the top portion of the bleacher seat structure is mounted on the lift mechanism and thus the lift mechanism in effect becomes a part of the bleacher unit itself. In such embodiment it is not contemplated that the lift mechanism will in normal use be separated from the bleacher unit but instead will become a more or less permanent part thereof. It should be understood, however, that in other embodiments of this invention the lift mechanism can be constructed and utilized as a separate unit in which case the lift mechanism can be used with more than one bleacher unit.

Proceeding further with the description of the operation, the lift mechanism, as shown in FIGS. 3, 7 and in the left-hand half of FIG. 2 is in its non-operative or down position with the weight of the bleacher unit 10 carried by carriage wheels 26 and not by the lift mechanism. When it is desired to move bleacher unit 10 it is first necessary to retract the bleacher unit from the position shown in FIG. 1 to that shown in FIG. 3. Next, the hydraulic ram 46 on each of the two spaced support assemblies 28 is energized by actuation of pump unit 45 causing the lift assemblies 30, to be moved upwardly on the guide rail assemblies 38, 38. This in turn will cause lift angles 62 to engage the bottoms of the bleacher footboards 24 and thus lift the entire bleacher unit 10 off the floor to the position shown on the right-hand half of FIG. 2. In such position the entire weight of the bleacher unit is supported by castors of the lift mechanism and the bleacher unit can then be rolled along the 7 floor to whatever location is desired.

FIGS. 9-14 show a second embodiment of the invention particularly adapted for handling a heavier type structure such as a retractable chair riser section. The modified lift mechanism is comprised of a wheeled support assembly 102 (FIG. 11) and a lift assembly 104 which are shown in assembled position in FIGS. 8, 9 and 10. As shown in FIGS. 8, 10 and 12. a spaced pair of assembled support and lift assemblies are fastened together by a horizontally disposed bottom support girder 106, rear cross braces 108, a front cross brace and a top support girder 112 between the tops of the two lift assemblies, all of which cooperate to produce a self-supporting unit.

Each support assembly 102 is comprised of a horizontally extending base 114 and a vertical guide rail assembly 116 mounted thereon. Guide rail assemblies 116 are rigidly supported on base members 114 by diagonal support braces 118, Each base 114 is provided with a pair of castors 120, 120 for Wheeling the entire unit along the floor when desired.

Each guide rail assembly 116 is comprised of a pair of spaced I-beams 122, 122'rigidly secured to each other by a plurality of connector plate members 124 welded therebetween as shown in FIG. 11. A suitable lifting means such as a hydraulic ram unit 126 having a piston 128 is mounted on support assembly 102 by means of a pair of support plates 130 and bolts 132.

Each lift assembly 104 is comprised of a pair of vertical channel members 134, 134 rigidly secured together in spaced back-to-back relationship by connector plates 136 welded there-between to form a box-like member. A plurality of lifting channel members 138 are fastened to channel members 134 at a plurality of vertically spaced points as clearly shown in FIGS. 8 and 9. It is noted (FIG. 8) that a pair of lifting channels 138 is provided at each vertical level to accommodate the heavier chair riser construction. Also mounted on the side of one of the vertical channels 134 is a gusset plate 140 adapted for cooperation with the lift ram 126 mounted on the wheeled support assembly. While some variation is contemplated it is preferred that the ratio of the height of said lift assembly 104 to the length of said base portion 114 is about 2 to 1.

As shown in FIGS. 8 and 9, lift assembly 104 is slidably supported on the guide rail assembly 1160f wheeled support assembly 102 with the I-beams 122, 122 of the guide assembly positioned inside the box-like lift assembly formed by vertical channels 134, 134.

A pair of alignment rollers 142, 142 are rotatably mounted between channels 134, 134 by bolts 144 (FIG. 13) which cooperate with spaced I-beams 122, 122 to prevent binding of the channels 134, 134 on the I-beams 1.22, 122 to thus insure a smooth sliding relationship between the two assemblies even under the heavy loads experienced when lifting an entire retractable chair riser section.

As shown in FIG. 8, when the lift mechanism is fully assembled, plate 140 on lift assembly 104 will be positioned directly over the end of operating piston 128 of ram 126 so that upon actuation of the ram the entire lift assembly 104 including lift channels 138 will be moved upwardly with respect to the support assembly 102.

To provide added stability to the chair riser section, bleacher section, or other structure used with the lift mechanism, a pair of stabilizer pins 146 are provided as shown in detail in FIG. 14. Pins 146 are slidably mounted in collars 148 welded to base members 114 of the lift mechanism and are positioned to register with sockets 150 mounted in the floor. Thus, when the lift mechanism is bolted or otherwise secured to the rear of the chair riser section, pins 146 will serve to provide some additional lateral stability to the chair riser section when such section is in use.

The operation of the modified lift mechanism shown in FIGS. 8-l4 is as follows. When it is desired to move the chair riser section the pins 146 are disengaged from sockets 150 and the hydraulic rams 126 are energized causing the lift assemblies 104, 104 to be moved upwardly on the guide rail assemblies 116, 116. This in turn will cause lift channels 138 to engage the chair riser section at a plurality of vertically spaced points to thus lift the entire section off the ground. In such position the entire weight of the bleacher unit is supported by castors 120 of the lift mechanism and the chair riser unit can then be rolled along the floor to the desired location.

Although two embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims. For example, while the lifting means shown in the drawings is in the form of a hydraulic ram other types of lifting mechanisms could be employed such as a mechanical jack operable either by hand or electric motor.

I claim:

1. A lift mechanism for moving bleacher units and the like comprising:

a pair of spaced support assemblies each including a horizontal base portion having wheels and a vertical guide rail assembly mounted on said base portion at the rear end thereof, said support assemblies being interconnected by bracing means to provide a selfsupporting structure adapted for positioning at the rear of a bleacher unit;

a pair of lift assemblies each slidably mounted on the guide rail assembly of said pair of support assemlies, each of said lift assemblies including a plurality of vertically spaced lift members fastened thereto and adapted for insertion into the bleacher units from the rear to provide engagement with the vertically spaced horizontally extending members of a bleacher unit; and

a lifting means mounted between each of said support assemblies and said lift assemblies and adapted when energized to move said lift assemblies upwardly with respect to said support assemblies.

2. A lift mechanism according to claim 1 in which each of said guide rail assemblies includes a pair of vertical tubular members and in which each of said lift assemblies includes a channel member slidably engaged with said tubular members.

3. A lift mechanism according to claim 2 in which each of said channel members is provided with a pair of retaining flanges to hold said channel members securely in place on said tubular members.

4. A lift mechanism according to claim 1 in which a roller means is provided between said lift assembly and said guide rail assembly.

5. A lift mechanism according to claim 1 in which each of said lifting means includes a hydraulic ram means mounted on a support assembly.

6. A lift mechanism according to claim 1 in which said lift assemblies are provided with seat and footboards mounted on the upper portion thereof to serve as the top seat structure of the bleacher unit.

7. A lift mechanism according to claim 8 in which each of said guide rail assemblies includes a pair of spaced ver tically extending I-beams.

8. A lift mechanism according to claim 7 in which each of said lift assemblies includes a box-like member slidably mounted on said I-beams.

9. A lift mechanism according to claim 1 in which each of said support assemblies is provided with a stabilizer pin adapted for engagement with a socket mounted in the floor.

10. A lift mechanism according to claim 1 in which the ratio of the height of said lift assemblies to the length of said base portions is about 2 to 1.

References Cited UNITED STATES PATENTS 2,183,057 12/1939 Albach et al. 529 2,968,841 1/1961 Vance 52143 X 2,983,968 5/1961 Wurn 52143 X 3,103,707 9/1963 Lappin et al. 529 3,107,399 10/1963 Murphy 5210 OTHER REFERENCES Safeway Spectator Seating by Safway Steel Products, Inc., Milwaukee, Wisconsin, cat. #65. 657, page 11 relied upon 159.

DAVID J. WJLLIAMOWSKY, Primary Examiner. HARRISON R. MOSELEY, Examiner. I. K BELL, Assistant Examiner. 

1. A LIFT MECHANISM FOR MOVING BLEACHER UNITS AND THE LIKE COMPRISING: A PAIR OF SPACED SUPPORT ASSEMBLIES EACH INCLUDING A HORIZONTAL BASE PORTION HAVING WHEELS AND A VERTICAL GUIDE RAIL ASSEMBLY MOUNTED ON SAID BASE PORTION AT THE REAR END THEREOF, SAID SUPPORT ASSEMBLIES BEING INTERCONNECTED BY BRACING MEANS TO PROVIDE A SELFSUPPORTING STRUCTURE ADAPTED TO POSITIONING AT THE REAR OF A BLEACHER UNIT; A PAIR OF LIFT ASSEMBLIES EACH SLIDABLY MOUNTED ON THE GUIDE RAIL ASSEMBLY OF SAID PAIR OF SUPPORT ASSEMLIES, EACH OF SAID LIFT ASSEMBLIES INCLUDING A PLURALITY OF VERTICAL SPACED LIFT MEMBERS FASTENED THERETO AND ADAPTED FOR INSERTION INTO THE BLEACHER UNITS FROM THE REAR TO PROVIDE ENGAGEMENT WITH THE VERTICALLY SPACED HORIZONTALLY EXTENDING MEMBERS OF A BLEACHER UNIT; AND A LIFT MEANS MOUNTED BETWEEN EACH OF SAID SUPPORT ASSEMBLIES AND SAID LIFT ASSEMBLIES UPWARDLY WITH ENERGIZED TO MOVE SAID LIFT ASSEMBLIES UPWARDLY WITH RESPECT TO SAID SUPPORT ASSEMBLIES. 